Step 2: Adjust the orientation

Step 3: Crop to a square

You can keep your little planet in a landscape frame.

I like to make mine a perfect square. It contrasts nicely with the little planet.

To do this, in the navigation menu select; Image > Canvas Size...

Make sure you turn of the constrain proportions setting is unlocked (chain icon between width and height values shows as broken), the set the width to equal the height (e.g 2880 x 2880 in the screenshot above).

Finally, make sure the offset lines up with the middle of your little planet.